Integrated Circuit / Printed Circuit Board Assembly and Method of Manufacture

ABSTRACT

An integrated circuit/printed circuit board (IC-PCB) assembly comprises a PCB and a heatsink plate. The PCB has a first side including a first patterned conductive layer with one or more thermal pads onto which one or more heat slugs of one or more ICs mount, and a second, opposing side including a second patterned conductive layer with a heatsink plate receiving pad onto which the heatsink plate mounts. The heatsink plate has one or more posts that project from a mounting surface of the heatsink plate, and when the heatsink plate is mounted to the heatsink plate receiving pad, each post extends from the second side of the PCB, through a matching hole in the PCB, and to an associated thermal pad located on the first side of the PCB.

BACKGROUND OF THE INVENTION

Printed circuit boards (PCBs) are used to provide mechanical support andelectrical connectivity between electrical components of an electricalcircuit or system. Integrated circuits (ICs) are one of the many typesof electrical components that are commonly mounted on a PCB, the othersincluding devices such as resistors, capacitors, inductors, diodes, andtransistors. In general, there are two approaches to mounting ICs onto aPCB. One approach known as “through-hole mounting” (THM) involvesinserting leads of a packaged IC through holes in the PCB and thensoldering the leads to conductive pads on the opposite side of the PCB.In the other approach, known as “surface mount technology” (SMT), theleads of the IC package are soldered to pads located on the same side ofthe PCB that the IC is mounted, or the IC is mounted to the PCB inunpackaged form as a bare “chip” or “die,” for example, by gluing the ICto the PCB and then welding fine wires between electrical connections onthe bare IC to conductive pads on the PCB (known as “chip on board” or“COB”) or by inverting the bare chip and securing it to the PCB usingballs of solder placed at locations on the PCB where electricalconnections to the chip are required (known as “flip chip on board”).

SMT has a number of advantages over THM. Some of these advantages followfrom not having to drill the many holes required for the ICs' and othercomponents' leads, which not only makes assembly faster and lessexpensive, but also allows the PCB to be manufactured with a higherdensity of electrical traces. SMT components are also usually lessexpensive to manufacture than THM components and SMT ICs can bemanufactured to have closer lead-to-lead spacings, resulting in overallsmaller component sizes and the PCB being able to accommodate a higherdensity of components.

Various IC packaging types have been developed over the years to supportSMT. One of the most widely used is the so-called “quad flat pack” or“QFP.” A QFP is a square- or rectangular-shaped package with leads thatproject from the package periphery and bend down in a “gull-wing” shapeso that they land on matching pads on the PCB surface. FIG. 1 is across-sectional drawing of a portion of a typical QFP IC-PCB assembly100, highlighting how the QFP 102 is surface-mounted to a top surface104 of the PCB 106. The QFP 102 comprises a plastic enclosure 108 thatencapsulates an IC 110, bond wires 112, a heat slug 114, and portions ofleads 116. The leads 116 project through the plastic enclosure 108,along the periphery of the QFP 102, i.e., along the plastic enclosure's108′s four sides, and are soldered to conductive pads 118 patterned in atop conductive layer 120 of the PCB 106. The bottom surface of the heatslug 114 is soldered, or glued using thermally conductive adhesive, to alanding pad 122 also formed in the top conductive layer 120.

Not all applications require the QFP 102 to include a heat slug 114 toconduct heat away from the IC 110. However, in circumstances where oneis needed, a plurality of thermal vias 124 (i.e., a “thermal via array124”) is commonly formed through the PCB 106. (See FIG. 2, which is aplan view of the landing pad 122, better illustrating the thermal viaarray 124.) The thermal vias 124 serve as paths that conduct heatgenerated by the IC 110 and collected by the heat slug 114 down to asecond conductive PCB layer 126. The second conductive PCB layer 126serves as a heatsink and also, typically, as a ground plane.

Although the thermal vias 124 are thermal conductors, each also has anelectrical resistance R and electrical inductance L, which areundesirable since they can, under some circumstances, adversely affectthe performance of the IC 110 and/or the ability of the IC-PCB assembly100 to adequately conduct heat away from the IC 110. The resistances ofthe thermal vias can be problematic since they contribute to I²R losses,and their inductances can be problematic since they result in a voltagedrop that increases with frequency. The combined voltage drop of thethermal via resistors and inductors can also cause the electricpotential of the heat slug 114 to undesirably deviate from true groundpotential and to vary with frequency. These problems may not be ofsignificant concern if the IC 110 does not operate at high powers andhigh frequencies, but they can be significant, and even unacceptable, ifthe IC 110 does in fact operate at high powers and/or high frequencies,such as is often the case in radio frequency (RF) applications. Forexample, if the IC 110 is an RFIC comprising an RF power amplifier(RFPA) designed to operate over a wide range of high frequencies, theinability to effectively conduct heat away from the RFPA can result inthe RFPA's power transistor(s) operating too hot and consequently beingunable to generate sufficient RF power. The RF output power generated bythe RFPA will also undesirably roll off at higher frequencies due to thefrequency-dependent voltage drop caused by the inductance of the thermalvia array 124. Some of these problems can be mitigated by employing arecessed ceramic flat pack assembly, for example. However, ceramic flatpacks and recessed mounting are expensive and typically reserved formilitary applications, where cost is not a major concern, in otherwords, are not an optimal solution for commercial applications.

It would be desirable, therefore, to have a surface-mount IC-PCBassembly and associated mounting method that are more effective atconducting heat away from and IC than described above, even forhigh-power RFICs, and at the same time are able to exploit the low costof plastic surface-mount-type packaging, for example, plastic-packagedQFPs.

BRIEF SUMMARY OF THE INVENTION

An integrated circuit/printed circuit board (IC-PCB) assembly and amethod of its manufacture are disclosed. An exemplary IC-PCB assemblycomprises a PCB and a heatsink plate. The PCB has a first side includinga first patterned conductive layer with one or more thermal pads ontowhich one or more heat slugs of one or more ICs mount, and a second,opposing side including a second patterned conductive layer with aheatsink plate receiving pad onto which the heatsink plate mounts. Theheatsink plate has one or more posts that project from a mountingsurface of the heatsink plate, and when the heatsink plate is mounted tothe heatsink plate receiving pad, each post extends from the second sideof the PCB, through a matching hole in the PCB, and to an associatedthermal pad located on the first side of the PCB.

Further features and advantages of the invention, including a detaileddescription of the above-summarized and other exemplary embodiments ofthe invention, will now be described in detail with respect to theaccompanying drawings, in which like reference numbers are used toindicate identical or functionally similar elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional drawing of a portion of a prior artintegrated circuit/printed circuit board (IC-PCB) assembly;

FIG. 2 is a plan view of the IC landing pad of the prior art IC-PCBassembly depicted in FIG. 1, further revealing the thermal via arrayformed through the IC landing pad and PCB and highlighting theundesirable thermal via resistance and inductance of each thermal via;

FIG. 3 is a cross-sectional drawing of a portion of an IC-PCB assembly,according to one embodiment of the present invention;

FIG. 4 plan view of the IC landing pad of the IC-PCB assembly depictedin FIG. 3, further revealing the single-hole IC landing pad design andthe top surface of the heatsink plate post;

FIGS. 5A and 5B are top and bottom perspective views of the single-postheatsink plate of the IC-PCB assembly depicted in FIG. 3, in accordancewith one embodiment of the present invention;

FIG. 6 is a perspective view a multi-post heatsink plate used in otherIC-PCB assemblies of the present invention;

FIGS. 7 and 8 are front side (top) and back side (bottom) plan views ofan exemplary PCB, illustrating how the two posts of the multi-postheatsink plate depicted in FIG. 6 are inserted into and reach throughfirst and second holes formed through the PCB, and showing the heatsinkplate receiving pad onto which the multi-post heatsink plate mounts;

FIG. 9 is a cross-sectional drawing of a portion of IC-PCB assembly thatincludes a multi-post heatsink plate similar to that depicted in FIG. 6,according to an embodiment of the present invention;

FIG. 10 is a block diagram of a dynamic power supply (DPS) transmitterincluding first and second radio frequency ICs (RFICs), which, whenintegrated in the IC-PCB assembly depicted in FIG. 9, exploit thelow-resistance, low-inductance, and high performance heat removalproperties afforded by the multi-post heatsink plate; and

FIG. 11 is a method of manufacturing an IC-PCB assembly similar to thatdepicted in FIG. 9, according to one embodiment of the presentinvention.

DETAILED DESCRIPTION

Referring to FIG. 3, there is shown a cross-sectional drawing of aportion of an integrated circuit/printed circuit board (IC-PCB) assembly300, according to an embodiment of the present invention. In general,the IC-PCB assembly 300 comprises three principal components: a PCB 302,an IC 304 with heat slug 306, and a heatsink plate 308. The PCB 302includes a non-conductive substrate 310, a first conductive (preferablycopper) layer 312, and second conductive layer (also preferably copper)314. The first conductive layer 312 is laminated to a top surface of thenon-conductive substrate 310 and is etched according to a predeterminedpattern to leave signal traces for electrically connecting componentsmounted on the PCB 302 and pads onto which leads of the variouscomponents are soldered. The second conductive layer 314 is laminated toa bottom surface of the non-conductive substrate 310 and also etched toleave a heatsink plate receiving pad 318 onto which the heatsink plate308 mounts. (Note that in this exemplary embodiment of the IC-PCBassembly 300, the PCB 302 has just a single non-conductive substrate 310and two conductive layers 312 and 314. However, it could alternativelycomprise a multi-layered laminate with more than two conductive layers,as will be appreciated by those of ordinary skill in the art.)

The IC 304 in the exemplary IC-PCB assembly 300 preferably comprises aquad flat pack (QFP), or other similar surface-mount IC package, withthe IC 304 enclosed in an enclosure or encapsulant 320 (plastic,preferably, to save costs) and the heat slug 306 accessible through anopening in the enclosure bottom. The exposed bottom surface of the heatslug 306 is soldered to an IC landing pad 322 (i.e., thermal pad 322)patterned in the first conductive layer 312 or attached to the thermalpad 322 using a thermally conductive adhesive. Wire bonds 324, alsoenclosed within the IC enclosure 320, provide the electrical connectionsbetween the IC 304 and leads 326, which project through the enclosure320, along the enclosure's four sides, and which are soldered to leadpads 328 also patterned in the first conductive layer 312 of the PCB302. The thermal pad 322 for the heat slug 306 and the lead pads 328onto which the IC's 304′s leads 326 are soldered can be more readilyobserved in the plan view drawing presented in FIG. 4. It should bementioned that although a QFP is preferred, the IC 304 can be mounted tothe PCB 302 using essentially any surface-mount technology, so long asthe IC 304 is also equipped with a heat slug. For example, aplastic-leaded chip carrier (PLCC) or leadless chip carrier (LCC) couldbe used. The IC 304 could also be surface mounted without a chip carrierand in unpackaged form, for example, as a chip-on-board (COB) over anunderlying and accompanying heat slug.

The heatsink plate 308 has a top surface (i.e., mounting surface) thatis soldered to the heatsink plate receiving pad 318 or attached to theheatsink plate receiving pad 318 using a thermally conductive adhesive.As the heatsink plate 308 is being positioned for mounting, a post 330projecting from the top surface of the heatsink plate 308 is insertedinto a single large via hole 332 formed through the PCB 302 and centeredat the middle of thermal pad 322, as can be best seen in FIG. 4.Preferably, and as can be best seen in FIG. 3, the post 330 has a lengththat results in the post's top surface being coplanar with the topsurface of the thermal pad 322. In this way, once the heatsink plate 308is mounted onto the heatsink plate receiving pad 318, both the thermalpad 322 and the top surface of post 330 are in direct physical andthermal contact with the IC's 304's heat slug 306. Note that whereas theheat slug 306 serves as a thermally conductive conduit between the post330 of the heatsink plate 308 and IC 304, it will also typically serve,though not necessarily, as a means for grounding the IC 304 to the PCB302, in which case the heatsink plate 308 and its post 330 not onlybring the heatsink to the top surface 303 of the PCB 302 but also bringall return currents to the top surface 303.

In one embodiment of the invention, the wall defining the via hole 332is plated (for example, with copper) after being formed during themanufacturing process, thereby providing an electrical connectionbetween the thermal pad 322 in the first conductive layer 312 on the top(front side) of the PCB 302 to the heatsink plate receiving pad 318 inthe second conductive layer 314 on the bottom (back side) of the PDCB302, and the diameter of the post 330 is made to be just slightlysmaller than the diameter of the via hole 332, so that when the post 330is inserted into the plated via hole 332, it fits snugly and makes goodthermal contact with the plated via hole 332. Compared to the via holearray 124 used in the prior art IC-PCB assembly 100 (see FIGS. 1 and 2and accompanying description), the large plated single via hole 332provides a superior electrical connection, even in the absence of thepost 330, including a lower inductance, regardless of the size of thepost 330. In another embodiment of the invention, the diameter of thepost 330 is made even smaller, in other words, so that the post 330 doesnot fit snugly within the plated via hole 332 but rather so that a smallgap is present around the post 330 when inserted into the plated viahole 332. The small gap is then filled with molten solder or a thermallyconductive (or thermally and electrically conductive) adhesive, duringthe time the heatsink plate 308 is being mounted onto the heatsink platereceiving pad 318 and/or during the time the IC's 340's heat slug 306 isbeing soldered to the thermal pad 322. Any gap between the top surfaceof the post 330 and top surface of the thermal pad 322, whetherintentionally or unintentionally formed, can also be filled (e.g., withsolder), during the time the IC heat slug 306 is being mounted to thethermal pad 322. It should be mentioned that although the post 330 ispreferably a cylinder with a circular cross section and the post's 330'scorresponding via hole 332 is also preferably circular, other geometriesare possible. For example, the post 330 could be a four-sided columnwith a square, rectangular, or trapezoidal cross section, or apolyhedron with a cross section having more than four sides.Additionally, although the cross section of the post 330 is preferablyof the same shape as the via hole 332 (e.g., both circular), theirshapes could be different. For example, the post 330 could be afour-sided column with a square cross section while the via hole 332 iscircular.

FIG. 5A is a top perspective view of the heatsink plate 308, betterhighlighting the shape of its post 330, which is preferably cylindricalwith a circular cross section. The single-post design is superior to thethermal via array approach used in prior art IC-PCB assemblies since itallows heat generated by the IC 304 and collected by the heat slug 306to be more efficiently and effectively conducted away from the IC. Inmost cases the thermal performance is so effective that low-cost plasticsurface-mount packaging for the IC 304 can be used, thus avoiding thehigh cost of ceramic packaging. The single-post design also minimizesI²R losses, and, unlike prior art thermal via arrays, provides a lowinductance path, which is especially important in circumstances wherethe IC 304 is an RFIC. Assembly is also simpler and less costly sinceonly a single large via hole 332 needs to be formed through the PCB 302to receive the single post 330. In one embodiment of the invention, theheatsink plate 308 is copper and its post 330 is formed using a metalstamping process, similar to that used in the manufacture of automotivemetal parts. (Note that when manufactured according to such a process, adivot 502 incidentally forms in the bottom of the heatsink plate 308, asillustrated in the bottom perspective view of the heatsink plate 308presented in FIG. 5B.) It should be mentioned that although a metalstamping process is preferred due to its simplicity and low cost, theheatsink plate 308 and its post 330 can be alternatively manufacturedusing milling, casting, a combination of stamping, milling and casting,or, in fact, using any suitable metal working or metal shaping process.

FIGS. 6-8 are drawings depicting a multi-post heatsink plate 602 (FIG.6) and related IC-PCB assembly, according to another embodiment of thepresent invention. In this exemplary embodiment, the heatsink plate 602is manufactured to have two posts 604 and 606 that serve to conduct heataway from two separate ICs (not shown) when mounted on the PCB 704.Similar to as in the single-post design described above, the multi-postheatsink plate 602 is soldered to a heatsink plate receiving pad 802formed in a conductive layer on the back side of the PCB 704 (see FIG.8) or glued to the heatsink plate receiving pad 802 using a thermallyconductive adhesive. Only two large holes 710 and 712 need to be formedthrough the PCB 704 in order to receive the two posts 604 and 606.Preferably, though not necessarily, the lengths of the two posts 604 and606 are trimmed as necessary so that when the multi-post heatsink plate602 is mounted to the heatsink plate receiving pad 802 the top surfacesof the two posts 604 and 606 are coplanar with the top surfaces ofcorresponding IC landing pads (thermal pads) 706 and 708 formed in a topconductive layer on the top side of the PCB 704 (see FIG. 7). In thisway, once the two ICs are mounted on the top side of the PCB 704, thethermal pad 706 and top surface of corresponding post 604 and thethermal pad 708 and top surface of corresponding post 606 are both indirect physical and thermal contact with the heat slugs of theirrespective ICs. Any gap between the top surface of the post 604 and topsurface of thermal pad 706 and any gap between the top surface of thepost 606 and thermal pad 708, whether intentionally or unintentionallyformed, can also or alternatively be filled (e.g., with solder) duringthe time the ICs' heat slugs are being mounted to the thermal pads 706and 708. To further enhance thermal and electrical connectivity, theinterior surfaces of the PCB defining the two large holes 710 and 712can be plated (e.g., with copper) prior to mounting the heatsink plate602 to the backside of the PCB 704. Finally, similar to as in thesingle-post design described above, the diameters of the posts 604 and606 can be made so that they either fit snugly in the plated via holes,or so that they do not fit snugly but rather so that small gaps arepresent around the posts 604 and 606 and between the plated via holes710 and 712. In the latter approach, the small gaps are filled withmolten solder or a thermally conductive (or thermally and electricallyconductive) adhesive during the time the heatsink plate 602 is beingmounted onto the heatsink plate receiving pad 802 and/or during the timethe ICs' heat slugs are being soldered to the thermal pads 706 and 708.

FIG. 9 is a cross-sectional drawing of a portion of an IC-PCB assembly900 that has been manufactured and assembled similar to that describedabove in reference to FIGS. 6-8. The IC-PCB assembly 900 comprises a PCB902, first and second radio frequency ICs (RFICs) 904 and 906, and aheatsink plate 908. In this exemplary embodiment of the invention, thesecond RFIC 906 is larger and generates more heat than does the firstRFIC 904. For this reason the thermal pad 910 onto which the heat slug912 of the second RFIC 906 is mounted has a larger top surface area thandoes the thermal pad 914 onto which the heat slug 916 of the first RFIC904 is mounted. The heatsink post 918 for the second RFIC 906 alsopreferably has, though not necessarily, a larger diameter D2 than thediameter D1 of the heatsink post 920 for the first RFIC 904.

In one particular embodiment of the IC-PCB assembly 900, and asillustrated in FIG. 10, the first RFIC 904 comprises a dynamic powersupply (DPS) 1002 that produces an envelope following power supplyvoltage (i.e., DPS voltage) VDD(t) and the second RFIC 906 comprises anRF power amplifier (RFPA) 1004. Together, the DPS 1002 and RFPA 1004form an RF “dynamic power supply transmitter” 1000 or “DPS transmitter”1000. Further details concerning the electrical design and operation ofvarious types of DPS transmitters may be found in the book: “DynamicPower Supply Transmitters, Envelope Tracking, Direct Polar and HybridCombinations,” The Cambridge R F and Microwave Series, First Edition,Cambridge University Press (2015), by Earl W. McCune.

RF power measurements taken on one particular RFIC 1004 assembledaccording to the IC-PCB assembly 900 depicted in FIG. 9 compared to RFpower measurements taken from the same RFIC but assembled according to aprior art IC-PCB assembly similar to that depicted in FIG. 1 reveal theeffectiveness of the IC-PCB assembly 900 at conducting heat away fromthe second RFIC 906. The measurements reveal that the particular RFPA1004 is capable of producing an RF output of up to 40 dBm (10W) @ 200MHz and up to 36 dBm (4 W) @ 3 GHz—nearly double the RF output powerthat the same RFIC 904 is able to produce at and between bothfrequencies when assembled using a thermal via array like that depictedin FIG. 1. The ability of the RFPA 1004 to produce essentially doublethe RF output power over the entire 3 GHz frequency range followsfrom: 1) the IC-PCB assembly's 900′s superior ability to conduct heataway from the second RFIC 906 (RFPA 1004); 2) the lower electricalresistance of the heatsink post 918 compared to the electricalresistance of the prior art thermal via array; and 3) the lowerelectrical inductance of the heatsink post 918 compared to theelectrical inductance of the prior art thermal via array.

FIG. 11 is a flowchart illustrating a method 1100 of manufacturing anIC-PCB assembly similar to that depicted in FIG. 9, in accordance withone embodiment of the invention. In this exemplary method 1100, it isassumed that all PCB signal traces and pads have been formed (e.g.,patterned and etched) on both sides of the PCB prior to the start of themethod 1100. However, it should be mentioned that those preliminarysteps could be considered as steps of the manufacturing method 1100itself. It should also be mentioned that the various steps in the method1100 are not necessarily performed in the order shown in the flowchart.Some step(s), for example step 1106, can be performed prior to or inparallel with (i.e., at the same time as) some of the earlier steps inthe method 1100. In first step 1102, two large via holes are formed(e.g., drilled, if the holes are circular) through the IC landing pads(thermal pads) 914 and 916. Next, at optional

Attorney Docket No.: 136-037US step 1104 the surfaces defining the viaholes are plated, e.g., with copper or some other thermally conductive(or electrically and thermally conductive) material. At step 1106 theheatsink plate 908 is manufactured, for example, by stamping the posts918 and 920 in a single solid bulk copper metal plate using a metalstamping machine. If necessary, this step 1106 may further includetrimming the stamped posts 918 and 920 to ensure they are of optimallength and shape. At step 1108, the manufactured heatsink plate 908 ismounted to the heatsink plate receiving pad 922 on the back side(bottom) of the PCB 902, for example, by soldering the heatsink plate908 to the heatsink plate receiving pad 922 or by gluing it to theheatsink plate receiving pad 922 using a thermally conductive (orthermally and electrically conductive) adhesive. As this mounting step1108 is being performed, the posts 918 and 920 are inserted into the twolarge via holes that were formed through the PCB 902 and thermal pads914 and 916 in step 1102. Preferably, after the posts 918 and 920 areinserted into their respective via holes, the top surface of each post918 and 920 is coplanar with the top major surface of its associatedthermal pad 910 or 914 and the posts 918 and 920 fit properly in theirrespective via holes. If the top surface of either post 918 or 920 isnot coplanar with its associated thermal pad 910 or 914 or either post918 or 920 does not have the desired shape (e.g., desired diameter ifthe posts 918 and 920 are cylindrically shaped), the trimming operationin step 1106 can be repeated and/or steps 1102 and 1104 can be performedagain before the heatsink plate 908 is permanently attached (bysoldering and/or gluing) to the heatsink plate receiving pad 922.Finally, once the heatsink plate 908 has been permanently affixed to theheatsink plate receiving pad 922, at step 1100 the first and second ICs904 and 906 are mounted on the front side (top) of the PCB by solderingand/or gluing the heat slugs 916 and 912 of the first and second ICs 904and 906 to their respective thermal pads 914 and 910 using a thermallyconductive (or thermally and electrically conductive) adhesive.Alternatively, the first and second ICs 904 and 906 and their respectiveheat slugs 916 and 912 may be mounted to the PCB before the heatsinkplate 908 is mounted to the heatsink plate receiving pad 922.

While various embodiments of the present invention have been described,they have been presented by way of example and not limitation. It willbe apparent to persons skilled in the relevant art that various changesin form and detail may be made to the exemplary embodiments withoutdeparting from the true spirit and scope of the invention. Accordingly,the scope of the invention should not be limited by the specifics of theexemplary embodiments but, instead, should be determined by the appendedclaims, including the full scope of equivalents to which such claims areentitled.

1. An integrated circuit / printed circuit board (IC-PCB) assembly,comprising: a PCB having a first side including a first patternedconductive layer with a thermal pad onto which an IC heat slug ismounted, and a second, opposing side including a second patternedconductive layer with a heatsink plate receiving pad; and a heatsinkplate having a mounting surface in thermal contact with the heatsinkplate receiving pad and a post that: projects from the mounting surface,extends through a hole in the PCB within the thermal pad, and thermallycontacts the IC heat slug.
 2. The IC-PCB assembly of claim 1, whereinthe post has a top surface that is generally coplanar with a top surfaceof the thermal pad.
 3. The IC-PCB assembly of claim 1, wherein the holeis plated with metal that electrically connects the thermal pad on thefirst side of the PCB to the heatsink plate receiving pad on the secondside of the PCB.
 4. The IC-PCB assembly of claim 1, wherein the IC andIC heat slug are surface- mounted to the PCB as a quad flat pack (QFP).5. The IC-PCB assembly of claim 1, wherein the IC is enclosed orencapsulated in a plastic enclosure.
 6. The IC-PCB assembly of claim 5,wherein the IC comprises a radio frequency IC (RFIC) having an RF poweramplifier (RFPA).
 7. The IC-PCB assembly of claim 6, wherein the RFPA isoperable to produce an RF output up to 10 W at 200 MHz and up to 4 W at3 GHz.
 8. A method of manufacturing an integrated circuit/printedcircuit board (IC-PCB) assembly, comprising: forming a first holethrough a PCB with the first hole within a first IC landing padpatterned in a first conductive layer on a first side of the PCB;shaping or working a thermally conductive metal plate to form a firstpost that projects from a major surface of the thermally conductivemetal plate; and mounting the thermally conductive metal plate to aheatsink pad patterned in a second conductive layer on a second,opposing side of the PCB, said mounting including inserting the firstpost through the first hole from the second side of the PCB andsoldering or gluing the major surface of the thermally conductive metalplate to the heatsink pad.
 9. The method of claim 8, wherein shaping orworking the thermally conductive metal plate includes working or shapingthe post so that it has a length that results in a top surface of thefirst post being generally coplanar with a top surface of the first IClanding pad after the thermally conductive metal plate is mounted to theheatsink pad on the second side of the PCB.
 10. The method of claim 8,further comprising mounting a first IC heat slug of a first IC to thefirst IC landing pad.
 11. The method of claim 8, wherein shaping orworking the thermally conductive metal plate to form the first postcomprises stamping the first post using a metal stamping machine. 12.The method of claim 8, further comprising plating the first hole withmetal to electrically connect the first IC landing pad patterned in thefirst conductive layer on the first side of the PCB to the heatsink padpatterned in the second conductive layer on the second side of the PCB.13. The method of claim 8, further comprising: forming a second holethrough the PCB with the second hole within a second IC landing padpatterned in the first conductive layer on the first side of the PCB;and shaping or working the thermally conductive metal plate to form asecond post that projects from the major surface of the thermallyconductive metal plate, wherein mounting the thermally conductive metalplate to the heatskink pad on the second side of the PCB furtherincludes inserting the second post through the second hole, from thesecond side of the PCB.
 14. The method of claim 13, wherein shaping orworking the thermally conductive metal plate to form the first andsecond posts comprises stamping the first and second posts using a metalstamping machine.
 15. The method of claim 13, further comprising:plating the first hole with metal to electrically connect the first IClanding pad patterned in the first conductive layer on the first side ofthe PCB to the heatsink pad patterned in the second conductive layer onthe second side of the PCB; and plating the second hole with metal toelectrically connect the second IC landing pad patterned in the firstconductive layer on the first side of the PCB to the heatsink padpatterned in the second conductive layer on the second side of the PCB.16. The method of claim 13, further comprising mounting a second IC heatslug of a second IC to the second IC landing pad.
 17. The method ofclaim 16, wherein the second IC landing pad has a larger surface areathan a surface area of the first IC landing pad, the second hole islarger than the first hole, and the second post is larger than the firstpost.
 18. An integrated circuit / printed circuit board (IC-PCB)assembly, comprising: a (PCB) having a first side with a first patternedconductive layer including first and second IC landing pads, a firsthole formed through the PCB within the first IC landing pad, a secondhole formed through the PCB and within the second IC landing pad, and asecond, opposing patterned conductive layer including a heatsinkreceiving pad; and a thermally conductive heatsink plate having amounting surface in thermal contact with the heatsink receiving pad andfirst and second posts that project from the mounting surface and extendinto the first and second holes.
 19. The IC-PCB assembly of claim 18,wherein first and second top surfaces of the first and second posts aregenerally coplanar with first and second top surfaces of the first andsecond IC landing pads.
 20. The IC-PCB assembly of claim 18, wherein thefirst and second posts are stamped projections formed by a metalstamping machine.
 21. The IC-PCB assembly of claim 18, wherein thesecond IC landing pad has a larger surface area than a surface area ofthe first IC landing pad, and the second post is larger than the firstpost.
 22. The IC-PCB assembly of claim 18, further comprising: a firstIC with a first heat slug mounted to the first IC landing pad; and asecond IC with a second heat slug mounted to the second IC landing pad.23. The IC-PCB assembly of claim 22, wherein the first and second ICscomprise first and second radio frequency ICs (RFICs).
 24. The IC-PCBassembly of claim 23, wherein the first RFIC comprises a dynamic powersupply (DPS) and the second RFIC comprises an RF power amplifier (RFPA)configured to receive a DPS voltage from the DPS.
 25. The IC-PCBassembly of claim 23, wherein the first and second RFICs aresurface-mounted to the PCB as quad flat packs (QFPs).
 26. The IC-PCBassembly of claim 23, wherein the first and second RFICs is eachenclosed or encapsulated in a plastic enclosure.
 27. The IC-PCB assemblyof claim 24, wherein the RFPA in the second RFIC is operable to producean RF output up to 10 W at 200 MHz and up to 4 W at 3 GHz.